Feature Request: Other angles besides 45º

[shannonturner]

Earlier this summer I'd considered other ways of providing more angles to work with, because having a grid made of squares makes diagonal lines at angles other than 45º pretty difficult. (For example, the none of the avenues of DC in https://metromapmaker.com/map/6otdXTC7 were really able to be represented very well)

Using the grid format has the advantage of simplicity, but it does have a few drawbacks as well.

I'd considered a grid made of tessellated hexagons instead, but this introduces its own set of problems, namely that straight lines are only possible in a single axis, either vertical or horizontal, depending on which direction the hexagons are oriented.

Only equilateral triangles, squares, and regular hexagons will tessellate; semi-regular tessellations would be possible (octagons with squares in the corners, say) but more complex to implement, possibly defeating the point -- it may be far simpler to implement a non-grid-based system.

One potential way would be to add a series of "layers", where each layer allows you to choose a tessellation shape (and direction, important for hexagons). Implementing it in this way would also potentially solve #47 and #67.